This invention pertains to the reaction of nitro compounds. More particularly, this invention pertains to the displacement of the .alpha.-nitro group of .alpha.-nitroesters, .alpha.-nitroketones, .alpha.-nitronitriles and .alpha.,.alpha.-dinitro compounds by treatment with certain salts of aliphatic nitro compounds.
The displacement of the aliphatic nitro group of .alpha.,p-dinitrocumene by a number of anions has been reported by Kornblum et al., J. Am. Chem. Soc., 90, 6219 (1968). This displacement reaction is ascribed to the facility with which radial anions are formed in nitro aromatic systems. A similar displacement reaction also has been reported for .alpha.,m-dinitrocumene by Kornblum et al., J. Am. Chem. Soc., 90, 6221 (1968). In both instances the presence of the aromatic nitro group is necessary in order to get displacement of the aliphatic nitro group.
Seigle and Hass, J. Org. Chem., 5, 100(1940), reported the reaction of the sodium salt of nitrocyclohexane with 2-bromo-2-nitropropane to give 1-(1-methyl-1-nitroethyl)-1-nitrocyclohexane. From the sodium salt of 2-nitropropane and 2-bromo-2-nitropropane they obtained 2,3-dimethyl-2,3-dinitrobutane. Other compounds prepared in like manner were 2,3-dimethyl-2,3-dinitropentane and 3,4-dimethyl-3,4-dinitrohexane. The method is limited to the preparation of .alpha.,.beta.-dinitro compounds, and only low yields were reported.
A series of nitro malonic esters have been prepared by van Tamelan and Van Zyl by reaction of the appropriate sodio malonic ester with 2-chloro-2-nitropropane. The reported compounds have the formula ##EQU1## wherein Z is methyl, ethyl, allyl, n-butyl, i-butyl, or i-amyl. This process is also limited in that a malonic ester must be used.
It is also known to prepare symmetrical .alpha.,.beta.-dinitro compounds by a dimerization reaction of mononitro compounds.
Tilney-Bassett and Waters, J. Chem. Soc., 1957, 3129, obtained 2,2,3-trimethyl-3-nitrobutyronitrile in poor yield by heating sodio 2-nitropropane with .alpha.-nitroisobutyronitrile under reflux in dry alcohol. The exact yield was not reported but the implication was that is was extremely low, and certainly so low that the reaction had no practical significance. The reaction was incidental to the work being reported and no details were given. There was no suggestion that the reaction could be extended to other compounds.